1. Field of the Invention
The present invention relates to a mounting member for polishing employed mainly in the fine polishing of for example semiconductor substrates such as silicon or glass substrates.
2. Description of the Related Art
Conventionally, polishing of polishing workpieces of various types such as semiconductor substrates of silicon or gallium arsenide etc. or glass substrates etc. for liquid crystal displays was performed using a system for example as shown in FIG. 2. In more detail, a sheet of continuous porous construction (carrier plate) 3 made of resin was fixed on to a lower base plate 1 using an adhesive (tacky adhesive) 2. A template 4 was mounted on this sheet 3 of continuous porous construction, and a hole portion 5 into which polishing workpiece 10 was fitted was formed on this template 4.
In order to perform polishing of polishing workpiece 10, polishing workpiece 10 is first of all fitted into hole portion 5 of template 4, and this polishing workpiece 10 is mounted on to sheet 3 of continuous porous construction. Next, upper base plate 6 is lowered whilst rotating lower base plate 1 and upper base plate 6, and polishing is performed for the required period by bringing a polishing pad 7 provided on the underside of this upper base plate 6 into contact with polishing workpiece 10. An aqueous solution (slurry) 11 containing polishing powder that is used for polishing is supplied to the polishing location.
With the polishing system described above, the polishing workpiece 10 is held on continuous porous sheet 3 by the employment of template 4 in combination with continuous porous sheet 3, so any large sliding movement of polishing workpiece 10 due to the moisture of aqueous solution 11 can be prevented.
However, with the polishing system described above, it is necessary to change the template 4 in accordance with the size and/or shape of each respective polishing workpiece 10 and it is also necessary to change the template 4 if it gets damaged. The lowering in the proportion of time in which the polishing operation is actually being carried out produced by these changes of the template is a factor that increases production costs.
Furthermore, by forming hole portion 5 rather larger than polishing workpiece 10, a gap 12 is produced between the outer surface of polishing workpiece 10 and the inner surface of hole portion 5, with the result that, when polishing is carried out, the polishing workpiece 10 is able to perform sliding movement by the extent of the gap 12, bringing it into contact (collision) with template 4. As a result, the edge portion of polishing workpiece 10 gets damaged, causing defective articles to be produced.
The need for improvement in respect of these factors has become an important challenge, particularly recently, in the polishing of very large silicon wafers or glass for liquid crystals constituting a workpiece 10.